Antibiotic susceptibility of luminous bacteria from shrimp farm environs of West Bengal

Abstract

<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"> Sensitivity of 175 isolates of luminous bacteria from various shrimp farming systems of West Bengal was tested against six antibiotics, viz., chloramphenicol (30µg), ciprofloxacin (5µg), co-trimoxazole (25µg), gentamycin (10µg), nitrofurantoin (300µg) and oxytetracycline (30µg). Besides, the minimum inhibitory concentration (MIC) of the antibiotics was determined against 60 isolates of <i style="">Vibrio harveyi</i>. The isolates were least susceptible to oxytetracycline followed by ciprofloxacin and nirofurantoin, and highly susceptible to chloramphenicol. <i style="">Vibrio harveyi</i> was the most resistant species. About 56% of the luminous isolates exhibited multiple antibiotic resistance. The MIC of oxytetracycline was observed to be in the range of 1.56->200 µg/ml. Majority of the isolates were inhibited at a concentration of 0.10-0.78 µg/ml of ciprofloxacin and 0.20-6.25 µg/ml of chloramphenicol. The observations on the antibiotic resistance did not indicate that the luminous bacteria of certain shrimp culture systems of West Bengal is developing resistance to broad-spectrum antibiotics. </smarttagtype>